Embodiments of the invention generally relate to imaging, and more particularly to reconstruction of computed tomography data.
In modern medicine, medical professionals routinely conduct patient imaging examinations to assess the internal tissue of a patient in a non-invasive manner. Furthermore, for industrial applications related to security or quality control, screeners may desire to non-invasively assess the contents of a container (e.g., a package or a piece of luggage) or the internal structure of a manufactured part. Accordingly, for medical, security, and industrial applications, X-ray imaging, such as X-ray computed tomography (CT) imaging, is useful for noninvasively characterizing the internal composition of a subject of interest. Likewise, other imaging modalities, such as magnetic resonance imaging (MRI), positron emission tomography (PET), and single photon emission computed tomography (SPECT), are useful in various non-invasive contexts.
For computed tomography imaging suitable for such applications, there are generally two types of image reconstruction approaches: analytical reconstruction and iterative reconstruction. Analytical approaches typically encompass direct reconstruction techniques, such as the filtered backprojection techniques. While analytical approaches may be computationally efficient, they may be undesirable in certain circumstances due to image quality issues and/or patient dose. Iterative reconstruction approaches, which iteratively compare and update an image based on models and data, may provide superior image quality and dose characteristics. However, iterative reconstruction techniques are generally computationally intensive and may be time consuming as well.